Improvement in sewing-machines



C. S.'GUSHMAN. Sewing-Machines. No, 141,332, 1 Patentedjuly 29,1873.

: Ill-"lum" UNITED STATES PATENT OEEIGE.

CYRUS S. CUSHMAN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO NESBIT D.STOOPS, OF SAME PLACE.

IMPROVEMENT IN SEWING-MACHINES.

Specification forming part of Letters Patent No. 141,332, dated July 29,1873; application liled June 4, 1873.

To all whom it may concern: l

Be it known that I, CYRUs S. UUsHMAN, of the city of Philadelphia andState of Pennsylvania, have invented certain Improvements inSewing-Machines, of which the following is a specification:

My invention consists of a combination of devices, hereinafter named,for elevating the presser-foot.

Figure 1 is a plan view of the improved machine. Fig. 2 is a sideelevation ofthe same. Fig. 3 is a top view of the partially-rotatingincline lever M. Fig. 4 is a top view of the intermediate lever O. Fig.5 is a side view of the pin Q. Fig. 6 is a top view of the bearingattachment I. Figs. 7 and 8 are elevations ot' the same at right anglesto each other. Fig. 9 is a side view of the vertical intermediatelifting-bar H. Fig. 10 is a top view of the clutch or grasping lever F.Figs. l1 and 12 are end and side views of the stop G.

Like letters in all the figures indicate the same parts.

A is the bed-plate, and B the arm, of an ordinary sewing-machine. pC isthe drivingshaft, provided at its rear end with a face carnwheel, E, tooperate the lever. D is the feedwheel. So far the devices mentioned areessentially the same as exist on other machines. F is a clutch orgrasping-lever,whose front end rests on the stop G, which surrounds thelifting-bar H, there being a vertical slot, af, in the clutch, (seen inFig. 10,) in which the ilattened part b 'of the lifting-rod H issituated, said part being somewhat smaller, and, being freed fromthe'grasp of the clutch in the descent of the rod, admits of the latterfalling upon the material to be sewed independent of the downward motionof the clutch, so as to automatically adapt its descent to any thicknessof cloth; and hence the operating device of the clutch, by elevating therear end of the same, gives a grasping action of the slot a of theclutch upon the ilattened part b of the liftingbar, causing theelevation -of the same a detinite distance above the material to besewed,

irrespective of its thickness; and, as the"- presser-foot is onlyrequired to move from the cloth just far enough to allow the latter topass freely under it, the vertical movements of the presser-foot arenecessarily so slight as to make very little jar or noise instead of theunpleasant th umpin g incidental to other modes of vibrating thepresser-foot. The lifting-bar H is supported by means of the bearings co of the attachment I, which is confined to the varm B at its lower endby means of the screw J, as seen in Fig. l, and being elevated out ofthe same by means of the partially-rotating inclined lever M, (seen indetail in Figs. l and 3,) as the lever is turned in the direction of thearrow, the presser-foot being swung around in the same direction, thearm h is caused to rest upon the upper end of the stock. The said arm fis adjustable on the bar by means of the set-screw j.y By lifting thepresser-foot at the completion of each stitch the material being sewedis swung around on the needle to make any form of gure stitched, andthus accomplish the great `desideratum of making the stitches of uniformlength. The clutch F is actuated by means of the combination therewithof the main lever N, operatedby the cam-wheel E and short intermediatelever O, which has its fulcrurn-bearings in the attachment I, as seen inFigs. 1 and 2, the rear end of the clutch resting between the steadyingupturned prongs k k of the front end of the lever 0. The clutch F isheld down by the tension-spring P, which bears its front end hard uponthe stop G, upon which it turns, as its rear end is thrown upward by theaction of the levers N O, so as to cause opposite corners of the slot ato grasp the flattened part b of the lifting-barH, and thus secure apositive upward movement of the presser-foot, as before stated; and as areverse movement is given to the levers N O by the cam-wheel E recedingfrom the friction-wheel on the lower end of the lever N, andthetension-spring P being thus permitted to pull the rear end of theclutch downward, the flattened part b of the lifting-barH is releasedfrom the grasp of the clutch, and the har continues to descend until thepresser-foot rests upon the material to be sewed, irrespective of thethickness of the latter, as before stated. The pin Q, which serves as afulcrum for the lever N, is provided with a screw-thread, l, at itsinner end to tit the screw-stem on of the pin R, which serves as afulorum for the needle-operating lever. These two fulcrulnpins are thussecured to the arm B by means of the single nut l. I make the pinslightly tapering, as seen more clearly in Fig. 5, for setting it uponthe screw-stem m to compensate for the wear.

I am aware that it is not new to elevate a presser-foot in a variablemanner, as in PatentNO. 134,509.

I claim as my inventionv 1. The clutch F, in combination with thepresser lifting-bar H, stop G, and tensionspring P, for elevating thepresser-foot, substantiallly as described.

2. The pin Q having screw-thread l, in comn Witnesses:

THOMAS J. BEWLEY, STEPHEN UsTIoK.

